90 research outputs found

    Improving a Terahertz Time-Domain Spectroscopy Apparatus Using Neodymium Magnets

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    Abstract. The signal-to-noise ratio obtained from terahertz time-domain spectroscopy is significantly affected by the low available power of terahertz waves. We constructed a terahertz-wave source with emission power enhanced by a magnetic field. The emitter is composed of an InAs wafer and two neodymium magnets. The emitter was irradiated by femtosecond laser pulses. The data quality of terahertz spectroscopic measurements was evaluated, and reduction of error in the data obtained due to the terahertz power enhancement was observed

    Restriction-modification system with methyl-inhibited base excision and abasic-site cleavage activities

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    The restriction-modification systems use epigenetic modification to distinguish between self and nonself DNA. A modification enzyme transfers a methyl group to a base in a specific DNA sequence while its cognate restriction enzyme introduces breaks in DNA lacking this methyl group. So far, all the restriction enzymes hydrolyze phosphodiester bonds linking the monomer units of DNA. We recently reported that a restriction enzyme (R.PabI) of the PabI superfamily with half-pipe fold has DNA glycosylase activity that excises an adenine base in the recognition sequence (5′-GTAC). We now found a second activity in this enzyme: at the resulting apurinic/apyrimidinic (AP) (abasic) site (5′-GT#C, # = AP), its AP lyase activity generates an atypical strand break. Although the lyase activity is weak and lacks sequence specificity, its covalent DNA–R.PabI reaction intermediates can be trapped by NaBH[subscript 4] reduction. The base excision is not coupled with the strand breakage and yet causes restriction because the restriction enzyme action can impair transformation ability of unmethylated DNA even in the absence of strand breaks in vitro. The base excision of R.PabI is inhibited by methylation of the target adenine base. These findings expand our understanding of genetic and epigenetic processes linking those in prokaryotes and eukaryotes

    Serum and urinary ferritin levels in patients with rheumatoid arthritis

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    The serum and urinary ferritin levels in 52 RA patients were measured by the 2-site immunoradiometric assay method. Serum ferritin levels in RA patients correlated with C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) but not with serum iron levels and hemoglobin concentrations, although they were within the normal range. High serum ferritin levels were associated with sera with hyper gamma-globulin and rheumatoid factors. In sequential studies, serum ferritin changed in parallel with ESR, CRP and disease activity in a majority of the patients. The urinary ferritin levels and u/s ratios in some RA patients were higher than control values. Higher values were found particularly in the group of patients under gold therapy but not in groups under other treatments.</p

    Phase I study of combined therapy with vorinostat and gefitinib to treat BIM deletion polymorphism-associated resistance in EGFR-mutant lung cancer (VICTROY-J) : a study protocol

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    The BIM deletion polymorphism is reported to be associated with poor outcomes of epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) treated with EGFR-TKIs, including gefitinib. We have shown that a histone deacetylase inhibitor, vorinostat, can epigenetically restore BIM function and apoptosis sensitivity to EGFR-TKIs in EGFR-mutant NSCLC cells with BIM deletion polymorphisms. The purpose of this study is to determine the feasibility of combined treatment of vorinostat with gefitinib in BIM deletion polymorphism positive EGFR-mutant NSCLC patients. BIM deletion polymorphism positive EGFR mutant NSCLC patients treated with at least one EGFR-TKI and one regimen of chemotherapy are being recruited to this study. Vorinostat (200-400mg) will be administered orally once daily on days 1-7, and gefitinib 250 mg orally once daily on days 1-14. With a fixed dose of gefitinib, the dose of vorinostat will be escalated following a conventional 3+3 design. The primary endpoint is to define the maximum tolerated dose (MTD) of vorinostat combined with 250 mg of gefitinib. This is the first phase I study of combined therapy with vorinostat and gefitinib for NSCLC patients double selected for an EGFR mutation and BIM deletion polymorphism

    ADAR1 is a promising risk stratification biomarker of remnant liver recurrence after hepatic metastasectomy for colorectal cancer

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    Adenosine-to-inosine RNA editing is a process mediated by adenosine deaminases that act on the RNA (ADAR) gene family. It has been discovered recently as an epigenetic modification dysregulated in human cancers. However, the clinical significance of RNA editing in patients with liver metastasis from colorectal cancer (CRC) remains unclear. The current study aimed to systematically and comprehensively investigate the significance of adenosine deaminase acting on RNA 1 (ADAR1) expression status in 83 liver metastatic tissue samples collected from 36 patients with CRC. The ADAR1 expression level was significantly elevated in liver metastatic tissue samples obtained from patients with right-sided, synchronous, or RAS mutant-type CRC. ADAR1-high liver metastasis was significantly correlated with remnant liver recurrence after hepatic metastasectomy. A high ADAR1 expression was a predictive factor of remnant liver recurrence (area under the curve = 0.72). Results showed that the ADAR1 expression level could be a clinically relevant predictive indicator of remnant liver recurrence. Patients with liver metastases who have a high ADAR1 expression requires adjuvant chemotherapy after hepatic metastasectomy

    AXL confers intrinsic resistance to osimertinib and advances the emergence of tolerant cells

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    A novel EGFR-tyrosine kinase inhibitor (TKI), osimertinib, has marked efficacy in patients with EGFR-mutated lung cancer. However, some patients show intrinsic resistance and an insufficient response to osimertinib. This study showed that osimertinib stimulated AXL by inhibiting a negative feedback loop. Activated AXL was associated with EGFR and HER3 in maintaining cell survival and inducing the emergence of cells tolerant to osimertinib. AXL inhibition reduced the viability of EGFR-mutated lung cancer cells overexpressing AXL that were exposed to osimertinib. The addition of an AXL inhibitor during either the initial or tolerant phases reduced tumor size and delayed tumor re-growth compared to osimertinib alone. AXL was highly expressed in clinical specimens of EGFR-mutated lung cancers and its high expression was associated with a low response rate to EGFR-TKI. These results indicated pivotal roles for AXL and its inhibition in the intrinsic resistance to osimertinib and the emergence of osimertinib-tolerant cells

    KaPPA-View4: a metabolic pathway database for representation and analysis of correlation networks of gene co-expression and metabolite co-accumulation and omics data

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    Correlations of gene-to-gene co-expression and metabolite-to-metabolite co-accumulation calculated from large amounts of transcriptome and metabolome data are useful for uncovering unknown functions of genes, functional diversities of gene family members and regulatory mechanisms of metabolic pathway flows. Many databases and tools are available to interpret quantitative transcriptome and metabolome data, but there are only limited ones that connect correlation data to biological knowledge and can be utilized to find biological significance of it. We report here a new metabolic pathway database, KaPPA-View4 (http://kpv.kazusa.or.jp/kpv4/), which is able to overlay gene-to-gene and/or metabolite-to-metabolite relationships as curves on a metabolic pathway map, or on a combination of up to four maps. This representation would help to discover, for example, novel functions of a transcription factor that regulates genes on a metabolic pathway. Pathway maps of the Kyoto Encyclopedia of Genes and Genomes (KEGG) and maps generated from their gene classifications are available at KaPPA-View4 KEGG version (http://kpv.kazusa.or.jp/kpv4-kegg/). At present, gene co-expression data from the databases ATTED-II, COXPRESdb, CoP and MiBASE for human, mouse, rat, Arabidopsis, rice, tomato and other plants are available

    建学の精神の徹底を図る初年次教育の実践と課題 ―ホスピタリティ概論の分析から―

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    本研究は、2017年度から始まった本学の初年次教育を定着させるとともに、新入生が大学での教育を理解し、建学の精神に代表される理念やディプロマポリシーを自分のものとして捉え、その実現に向けた主体的な学修の基盤を構築するという初年次教育の目標の達成を図ることにある。このためには、彼らの特性をとらえるとともに、彼らが初年次教育をどのように捉え、理解したかを把握しなければならない。そこで初年次教育の科目の一つとして開設された「ホスピタリティ概論」を活用して、全受講生を対象とした2つの調査を3年間実施した。1つ目の調査は入学当初の学生像をとらえ授業展開に生かすために学生の特徴を把握するものであり、第1回目の授業で実施された。2つ目の調査は授業内容の理解度を評価するものであり、第10回目に実施された。これらの回答を年度と学科毎に集計、分析した。その結果、次のことが明らかになった。①オープンキャンパスへの参加や進学希望状況などの本学入学に至る経緯が学科によって異なること、そして、入学当初には心身に不安を抱いている学生が、どの学科にも相当数存在すること。3年間の調査によって各学科の学生の特色が明らかになり、学科毎の適切な学修支援方策の作成に向けた示唆が得られたこと。②この講義を受けて、建学の精神であるホスピタリティの獲得に大学が力を入れており、その実現が求められていると多くの学生が認識していること、及び、本科目の重点目標である多様性の理解力の育成につながる他学科の学生とのコミュニケーションの機会に意義を見出していること等から、授業の目標達成に向けた順調な歩みが見られること。これらの結果及び他の科目の報告から、初年次教育が定着しつつあること、そして、その目標達成に向けた歩みが順調であると判断した。ただ、更なる充実のための課題も浮かび上がっている
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